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Tracking system and pulse sequences to monitor the position of a device using magnetic resonance

  • US 5,307,808 A
  • Filed: 04/01/1992
  • Issued: 05/03/1994
  • Est. Priority Date: 04/01/1992
  • Status: Expired due to Term
First Claim
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1. A real-time magnetic resonance (MR) tracking system comprising:

  • a) an invasive device adapted to be inserted into a subject;

    b) static magnetic field means for applying a homogeneous magnetic field having substantially uniform amplitude over the subject;

    c) radiofrequency (rf) transmitter means for transmitting rf energy of a selected duration, amplitude and frequency into the subject to cause nutation of a selected ensemble of spins in the subject;

    d) gradient means adapted for varying the amplitude of the magnetic field in at least one spatial dimension over the subject over time causing the selected ensemble of spins to emit an MR response signal;

    e) detection means attached to the invasive device adapted for detecting the MR response signal from the selected ensemble of spins within the subject;

    f) calculation means responsive to the detection means adapted for calculating a location of the invasive from the detected MR response signal;

    g) controller means coupled to the rf transmitter means, the detection means, the calculation means and the gradient means adapted for activating the rf transmitter means, the detection means, the calculation means and the gradient means according to a desired MR tracking sequence repeatedly for the purpose of tracking the invasive device in real-time; and

    h) display means responsive to the calculation means adapted for displaying the location of the invasive to an operator.

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